Phosphorylation regulates TRPV1 association with β-arrestin-2

2013 ◽  
Vol 451 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Elaine D. Por ◽  
Ruben Gomez ◽  
Armen N. Akopian ◽  
Nathaniel A. Jeske

Post-translational modifications in TRPV1 (transient receptor potential vanilloid 1) play a critical role in channel activity. Phosphorylation of serine/threonine residues within the N- and C-termini of TRPV1 are implicated in receptor sensitization and activation. Conversely, TRPV1 desensitization occurs via a calcium-dependent mechanism and leads to receptor de-phosphorylation. Importantly, we recently demonstrated that TRPV1 association with β-arrestin-2 is critical to receptor desensitization via its ability to scaffold the phosphodiesterase PDE4D5 to the receptor, regulating TRPV1 phosphorylation. In the present study, we demonstrate that phosphorylation of TRPV1 and β-arrestin-2 regulates this association at the membrane. Under serum-free media conditions, we observed a significant decrease in TRPV1 and β-arrestin-2 association in transfected CHO (Chinese-hamster ovary) cells. Pharmacological activation of the kinases PKA (protein kinase A) and PKC (protein kinase C) led to a robust increase in TRPV1 and β-arrestin-2 association, whereas inhibition of PKA and PKC decreased association. Previously, we identified potential PKA residues (Ser116, Thr370) in the N-terminus of TRPV1 modulated by β-arrestin-2. In the present study we reveal that the phosphorylation status of Thr370 dictates the β-arrestin-2 and TRPV1 association. Furthermore, we demonstrate that CK2 (casein kinase 2)-mediated phosphorylation of β-arrestin-2 at Thr382 is critical for its association with TRPV1. Taken together, the findings of the present study suggest that phosphorylation controls the association of TRPV1 with β-arrestin-2.

2014 ◽  
Vol 143 (5) ◽  
pp. 559-575 ◽  
Author(s):  
Jose Mercado ◽  
Rachael Baylie ◽  
Manuel F. Navedo ◽  
Can Yuan ◽  
John D. Scott ◽  
...  

Transient receptor potential vanilloid 4 (TRPV4) channels are Ca2+-permeable, nonselective cation channels expressed in multiple tissues, including smooth muscle. Although TRPV4 channels play a key role in regulating vascular tone, the mechanisms controlling Ca2+ influx through these channels in arterial myocytes are poorly understood. Here, we tested the hypothesis that in arterial myocytes the anchoring protein AKAP150 and protein kinase C (PKC) play a critical role in the regulation of TRPV4 channels during angiotensin II (AngII) signaling. Super-resolution imaging revealed that TRPV4 channels are gathered into puncta of variable sizes along the sarcolemma of arterial myocytes. Recordings of Ca2+ entry via single TRPV4 channels (“TRPV4 sparklets”) suggested that basal TRPV4 sparklet activity was low. However, Ca2+ entry during elementary TRPV4 sparklets was ∼100-fold greater than that during L-type CaV1.2 channel sparklets. Application of the TRPV4 channel agonist GSK1016790A or the vasoconstrictor AngII increased the activity of TRPV4 sparklets in specific regions of the cells. PKC and AKAP150 were required for AngII-induced increases in TRPV4 sparklet activity. AKAP150 and TRPV4 channel interactions were dynamic; activation of AngII signaling increased the proximity of AKAP150 and TRPV4 puncta in arterial myocytes. Furthermore, local stimulation of diacylglycerol and PKC signaling by laser activation of a light-sensitive Gq-coupled receptor (opto-α1AR) resulted in TRPV4-mediated Ca2+ influx. We propose that AKAP150, PKC, and TRPV4 channels form dynamic subcellular signaling domains that control Ca2+ influx into arterial myocytes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Kenichi Goto ◽  
Takanari Kitazono

Vascular endothelial cells regulate arterial tone through the release of nitric oxide and other diffusible factors such as prostacyclin and endothelium derived hyperpolarizing factors. Alongside these diffusible factors, contact-mediated electrical propagation from endothelial cells to smooth muscle cells via myoendothelial gap junctions, termed endothelium-dependent hyperpolarization (EDH), plays a critical role in endothelium-dependent vasodilation in certain vascular beds. A rise in intracellular Ca2+ concentration in endothelial cells is a prerequisite for both the production of diffusible factors and the generation of EDH, and Ca2+ influx through the endothelial transient receptor potential vanilloid 4 (TRPV4) ion channel, a nonselective cation channel of the TRP family, plays a critical role in this process in various vascular beds. Emerging evidence suggests that the dysregulation of endothelial TRPV4 channels underpins endothelial dysfunction associated with cardiovascular disease (CVD) risk factors, including hypertension, obesity, diabetes, and aging. Because endothelial dysfunction is a precursor to CVD, a better understanding of the mechanisms underlying impaired TRPV4 channels could lead to novel therapeutic strategies for CVD prevention. In this mini review, we present the current knowledge of the pathophysiological changes in endothelial TRPV4 channels associated with CVD risk factors, and then explore the underlying mechanisms involved.


2018 ◽  
Vol 45 (3) ◽  
pp. 1084-1096 ◽  
Author(s):  
Mengwen Qi ◽  
Chunfeng Wu ◽  
Zhouqing Wang ◽  
Li Zhou ◽  
Chen Men ◽  
...  

Background/Aims: Glycine plays an important role in regulating hippocampal inhibitory/ excitatory neurotransmission through activating glycine receptors (GlyRs) and acting as a co-agonist of N-methyl-d-aspartate-type glutamate receptors. Activation of transient receptor potential vanilloid 4 (TRPV4) is reported to inhibit hippocampal A-type γ-aminobutyric acid receptor, a ligand-gated chloride ion channel. GlyRs are also ligand-gated chloride ion channels and this paper aimed to explore whether activation of TRPV4 could modulate GlyRs. Methods: Whole-cell patch clamp recording was employed to record glycine-activated current (IGly) and Western blot was conducted to assess GlyRs subunits protein expression. Results: Application of TRPV4 agonist (GSK1016790A or 5,6-EET) increased IGly in mouse hippocampal CA1 pyramidal neurons. This action was blocked by specific antagonists of TRPV4 (RN-1734 or HC-067047) and GlyR (strychnine), indicating that activation of TRPV4 increases strychnine-sensitive GlyR function in mouse hippocampal pyramidal neurons. GSK1016790A-induced increase in IGly was significantly attenuated by protein kinase C (PKC) (BIM II or D-sphingosine) or calcium/calmodulin-dependent protein kinase II (CaMKII) (KN-62 or KN-93) antagonists but was unaffected by protein kinase A or protein tyrosine kinase antagonists. Finally, hippocampal protein levels of GlyR α1 α2, α3 and β subunits were not changed by treatment with GSK1016790A for 30 min or 1 h, but GlyR α2, α3 and β subunits protein levels increased in mice that were intracerebroventricularly (icv.) injected with GSK1016790A for 5 d. Conclusion: Activation of TRPV4 increases GlyR function and expression, and PKC and CaMKII signaling pathways are involved in TRPV4 activation-induced increase in IGly. This study indicates that GlyRs may be effective targets for TRPV4-induced modulation of hippocampal inhibitory neurotransmission.


Haematologica ◽  
2019 ◽  
Vol 105 (11) ◽  
pp. 2572-2583
Author(s):  
Shaoxin Yang ◽  
Wei Lu ◽  
Chong Zhao ◽  
Yuanmei Zhai ◽  
Yanyu Wei ◽  
...  

Remodeling of adipocyte morphology and function plays a critical role in prostate cancer development. We previously reported that leukemia cells secrete growth differentiation factor 15 (GDF15),which remodels the residual bone marrow (BM) adipocytes into small adipocytes and is associated with a poor prognosis in acute myeloid leukemia (AML) patients. However, little is known about how GDF15 drives BM adipocyte remodeling. In this study, we examined the role of the transient receptor potential vanilloid (TRPV) channels in the remodeling of BM adipocytes exposed to GDF15. We found that TRPV4 negatively regulated GDF15-induced remodeling of BM adipocytes. Furthermore, transforming growth factor-β type II receptor (TGFβRII) was identified as the main receptor for GDF15 on BM adipocytes. PI3K inhibitor treatment reduced GDF15-induced pAKT, identifying PI3K/AKT as the downstream stress response pathway. Subsequently, GDF15 reduced the expression of the transcription factor Forkhead box C1 (FOXC1) in BM adipocytes subjected to RNA-seq screening and Western blot analyse. Moreover, it was also confirmed that FOXC1 combined with the TRPV4 promoter by the Chip-qPCR experiments, which suggests that FOXC1 mediates GDF15 regulation of TRPV4. In addition, an AML mouse model exhibited smaller BM adipocytes, whereas the TRPV4 activator 4α-phorbol 12,13-didecanoate (4αPDD) partly rescued this process and increased survival. In conclusion, TRPV4 plays a critical role in BM adipocyte remodeling induced by leukemia cells, suggesting that targeting TRPV4 may constitute a novel strategy for AML therapy.


2019 ◽  
Vol 116 (18) ◽  
pp. 8869-8878 ◽  
Author(s):  
Shangyu Dang ◽  
Mark K. van Goor ◽  
Daniel Asarnow ◽  
YongQiang Wang ◽  
David Julius ◽  
...  

TRPV5 (transient receptor potential vanilloid 5) is a unique calcium-selective TRP channel essential for calcium homeostasis. Unlike other TRPV channels, TRPV5 and its close homolog, TRPV6, do not exhibit thermosensitivity or ligand-dependent activation but are constitutively open at physiological membrane potentials and modulated by calmodulin (CaM) in a calcium-dependent manner. Here we report high-resolution electron cryomicroscopy structures of truncated and full-length TRPV5 in lipid nanodiscs, as well as of a TRPV5 W583A mutant and TRPV5 in complex with CaM. These structures highlight the mechanism of calcium regulation and reveal a flexible stoichiometry of CaM binding to TRPV5.


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